Speedometer and calibration .
Discussion
Not actually got around to trying to fit it yet but have bought a Digitech speedo corrector to hopefully correct the speedo in my S3.
Whos got those size tyres ?
225/50r16 vs 235/45r17 Tire Comparison Side By Side
225/50-16 235/45-17 Difference
Diameter inches (mm) 24.86 (631.4) 25.33 (643.3) 0.47 (11.9) 1.9%
Width inches (mm) 8.86 (225) 9.25 (235) 0.39 (10) 4.4%
Circum. inches (mm) 78.09 (1983.6) 79.57 (2020.99) 1.47 (37.38) 1.9%
Sidewall Height inches (mm) 4.43 (112.5) 4.16 (105.75) -0.27 (-6.75) -6%
Revolutions per mile (km) 811.32 (504.13) 796.32 (494.81) -15.01 (-9.33) -1.8%
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SILICONEKID 345HP 12.03 said:
blaze_away said:
Well its not a tyre size issue
The rolling circumferences are identical
245/50/16 199mm
245/45/17 199mm
So its got to be the sender, electronics or speedo.
I would suggest starting with a clean and adjust of the sender on the dif.
Whos got those size tyres ?The rolling circumferences are identical
245/50/16 199mm
245/45/17 199mm
So its got to be the sender, electronics or speedo.
I would suggest starting with a clean and adjust of the sender on the dif.
235/45/17 is 2019 mm
Vs standard tyre size (thats what my handbook says)
245/50/16 is 2045 mm
Same outcome though only 1% difference so tyre size isnt the cause.
....I shouldnt do mental arithmetic when half asleep
blaze_away said:
Ooops my mistake
235/45/17 is 2019 mm
Vs standard tyre size (thats what my handbook says)
245/50/16 is 2045 mm
Same outcome though only 1% difference so tyre size isnt the cause.
....I shouldnt do mental arithmetic when half asleep
I thought standard rear tyres are 225/50/16 except some early cars came with 225/55/16235/45/17 is 2019 mm
Vs standard tyre size (thats what my handbook says)
245/50/16 is 2045 mm
Same outcome though only 1% difference so tyre size isnt the cause.
....I shouldnt do mental arithmetic when half asleep
My last Chimaera had 245/45 x 16 on the rear. I think they were also frequently fitted to the 500s and Griffs.
The diameter is actually slightly less than a 225/50 x 16 (4.5mm) and less than 1%.
Compared to 225/55 x 16 though, it's over 4%. I doubt TVR recalibrated the Speedos when they went away from 225/55 x 16 tyres.......
The diameter is actually slightly less than a 225/50 x 16 (4.5mm) and less than 1%.
Compared to 225/55 x 16 though, it's over 4%. I doubt TVR recalibrated the Speedos when they went away from 225/55 x 16 tyres.......
phillpot said:
Not actually got around to trying to fit it yet but have bought a Digitech speedo corrector to hopefully correct the speedo in my S3.
Hi Phillpot, did this unit work for you?Regards
Tyre size couldn't create the 20%+ difference that Daz mentions.
And anyway, his speedo error is not consistent.
I would give Jodie Wiles at Python Racing a call, Daz. 01206 820044. He will be able to tell you what the likely problem is.
If he is able to fix speedo problems, he normally does such fixes in a week, not the several months that (not so) Speedy Cables take.
Also, you could talk to Mat Smith about it, as your car is going to him soon.
He will be able to whip the speedo out and send it to Jodie for you, and/or he will be able to check and adjust the sender position if that is the problem.
And anyway, his speedo error is not consistent.
I would give Jodie Wiles at Python Racing a call, Daz. 01206 820044. He will be able to tell you what the likely problem is.
If he is able to fix speedo problems, he normally does such fixes in a week, not the several months that (not so) Speedy Cables take.
Also, you could talk to Mat Smith about it, as your car is going to him soon.
He will be able to whip the speedo out and send it to Jodie for you, and/or he will be able to check and adjust the sender position if that is the problem.
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